Choosing the best green tea extract for weight loss isn’t easy. It must have the right amount of polyphenols without caffeine and not have any fillers or binders. Our green tea extract meets all these needs while also following strict manufacturing guidelines to ensure purity.
What is green tea extract?
Green tea is a specific way to prepare the leaves of Camellia sinensis (tea plants). Tea leaves are picked, heated, dried, and rolled into the small flakes we might be familiar with in tea bags. There’s very little processing done to prepare green tea. Green tea isn’t oxidized, meaning it’s closer to leaves straight off the bush (as opposed to black or oolong tea).
Green tea extract is a highly concentrated form of green tea. Rather than infusing the tea leaves in water like you would to make a cup of tea or blending them into a powder to make matcha, caffeine and catechins are extracted from tea leaf scraps and emulsified into a powder. Some companies will strip the antioxidants and caffeine from the leaves themselves instead.
A few choice micronutrients make green tea such a holistically healthy substance. We’ll be focusing on polyphenols, catechins, and epigallocatechin gallate (EGCG), but green tea also offers:
- L-theanine, an amino acid that can help soothe and focus your mind
- Vitamin B2
- Vitamin C
- Vitamin E
- Folic acid
- Gamma-aminobutyric acid (GABA)
- Potassium
- Calcium
- Phosphorus
Polyphenols
Many different plants contain polyphenols, compounds that help avoid pathogens and damage from UV radiation. When we eat plants rich in polyphenols, we gain some of these benefits through antioxidants. They aren’t vital nutrients like vitamins or zinc, but they help offset environmental free radical accumulation, keeping your health steady as you age.
There are thousands of polyphenol varieties. Some that you might encounter include:
- Flavonoids, like quercetin and catechins
- Polyphenolic amides, like capsaicin found in chili peppers
- Phenolic acids, like lignans found in flaxseed
- Ellagic acid, found in berries
Specifically, green tea contains flavonoids. Flavonoids are the largest group of polyphenols, containing over 5,000 different compounds that affect everything from coloring to taste to metabolites. These include:
- Procyanidins (like tannins found in red wine)
- Quercetin (found in apples, onions, and berries)
- Isoflavones (such as genistein and daidzein, found in soy and legumes)
- Catechins (found in green tea)
Catechins
Catechins are a specific kind of flavonoid. Green tea is one of the best dietary sources of catechins, but they’re also commonly found in:
- Cocoa
- Tea
- Prunes
- Acai fruit
- Apples
- Pears
- Peaches
- Barley
Catechins are known for their intense antioxidative properties. They can help our body absorb healthy foods better, protect our skin from UV damage, and minimize inflammation associated with allergies and inflammatory bowel disease.
There are four different types of catechins found in green tea:
- Epicatechin
- Epicatechin-3-gallate
- Epigallocatechin
- Epigallocatechin gallate (EGCG)
These catechins exist in large quantities in green tea. The oxidizing process to make black and oolong tea converts these polyphenols into other antioxidant polyphenols (such as theaflavin).
Epigallocatechin gallate (EGCG)
Of the four kinds of catechins mainly found in green tea, EGCG is the powerhouse. It’s the most common kind of catechin, and scientists are quickly discovering that it significantly impacts our health.
Its protective effects are vast, regulating multiple cancer-related pathways and helping to modify your epigenetics. In doses between 107mg and 856mg per day, it can lower your LDL (“bad” cholesterol) levels. It’s also the primary chemical thought to be responsible for green tea’s thermogenic properties, meaning more EGCG can help you lose weight.
This doesn’t mean that EGCG or green tea is a cancer cure or that it’ll give you a perfect body overnight. Instead, EGCG’s beneficial properties keep your body running at peak functioning.
Benefits of green tea
There are dozens of potential applications for green tea extract, but most of them still need more research before we can say they work for sure. Some theoretical properties of green tea include:
- Anti-inflammatory
- Anti-arthritic
- Anti-bacterial
- Anti-angiogenic (stopping or slowing tumor growth)
- Antiviral
- Neuroprotective
Based on these features, it’s proposed that green tea could help fight or prevent:
- Several types of cancer
- Cardiovascular diseases
- Type 2 diabetes
- High cholesterol
- High-fat diet-induced obesity
- Metabolic syndrome
- Herpes (specifically HSV-1)
- Genital warts
- Alzheimer’s disease
- Parkinson’s disease
- Dementia
Obviously, these are big shoes to fill. And most of these proposed benefits are still theories or only tested in animal models, meaning that we don’t know for sure if green tea can help humans in the same way. The list of diseases and disorders that it’s thought to cure stretches on longer than this article. If you’ve been prescribed medication by your doctor, don’t switch it out for a green tea supplement without consulting them first.
Research-backed benefits
There’s substantial evidence that green tea extract can kickstart weight loss (or keep you from gaining weight) by inducing thermogenesis. Thermogenesis is the process that makes your body generate extra heat to burn fat. Weight loss supplements and medications rely on this mechanism to help you lose weight, which is why you’re likely to see green tea extract listed as an ingredient in their Supplement Facts lists.
Polyphenols are potent antioxidants. We know that antioxidants have a huge range of health benefits because they can stop or slow damage to your cells from free radicals. Free radicals happen naturally from things like digesting food but can also be caused by environmental pollution or cigarette smoke. Over time, free radicals can build up excessively to cause oxidative stress, which can then cause things like cardiovascular disease, type 2 diabetes, neurodegenerative diseases, and cancer.
Since antioxidants interfere with this oxidative damage, you might see marketing that antioxidants can prevent those disorders and diseases. That’s not entirely true, but it’s also not completely wrong. Taking green tea supplements won’t delay a cancer diagnosis, but it might help slow cellular damage that could lead to it.
Green tea extract versus drinking tea
The differences between green tea extract and steeped tea play out in dosing. One cup of green tea made from a tea bag at home has about 100-150mg of polyphenols (about 75% of which are EGCG when brewed correctly). High-quality green tea extracts range from 45% to 50% EGCG, resulting in a lower EGCG-to-polyphenol ratio but more EGCG overall.
Most studies look at the amount of EGCG in each serving to determine a healthy dose. Taking about 350mg of EGCG daily is often enough to receive these benefits without any harm, though studies have shown that you can take up to 675mg without risking your health. Doses upward of 800mg EGCG daily (or about 1,500mg of green tea extract per day) can cause liver damage in some people.
Our top picks have between 250 and 450mg of EGCG per serving. To get the same amount of EGCG (and the same health benefits) as one serving of our favorite green tea extracts, you’d need to drink 2-4 cups of green tea. You can get the same benefits with less caffeine from a concentrated extract.
Insider Tip: Polyphenols taste bitter, so green tea that’s less sweet is more likely to be better for you. (As a bonus, green tea extract capsules remove bitter flavors from the equation altogether.)
Stability
Green tea extract is more stable long-term than brewed green tea. Green tea is best brewed at a low temperature (about 180° F). Once you begin steeping the tea, its polyphenols start to degrade. This occurs faster at higher temperatures. Green tea extract preserves a vast majority of these (between 95 and 98% on average), allowing you to get the most benefit without pulling out a thermometer every time you want a cup of tea.
On the other hand, solids (including powders inside capsules like most green tea extracts) are harder for your body to digest. It takes a while to break a solid into small, soluble pieces, and the longer it takes to reach peak solubility, the more proteins and chemicals degrade before you can use them. This means that while green tea extract might get you more polyphenols faster, your body might not be absorbing them in the same way. Most extracts have enough polyphenols to offset this, however.
Who should avoid green tea extract?
There are a few problems that can stem from taking green tea extract. Most of them occur when you take a high dose (2,000mg or more) every day and are made worse by taking them on an empty stomach. Be sure to take your green tea extract with food to avoid stumbling into adverse side effects.
The National Institutes of Health recommends staying away from green tea extract if you take beta-blockers like nadolol. In high doses, green tea can lower the amount of blood in your body, so it interacts poorly with medications used for high blood pressure and heart problems.
Some green tea extracts can cause stomach irritation. This is partially related to their caffeine content and partly associated with how polyphenols interact with the GI system. The easiest way to combat feelings of nausea is to take your green tea extract with food. If they persist, you might consider trying a decaffeinated green tea extract like Life Extension’s Decaffeinated Mega Green Tea Extract. Green tea naturally contains caffeine, though very few extracts have more than the average cup of coffee (100mg) per serving. (That’s another big perk.)
If you’re pregnant or lactating, a decaffeinated green tea extract should be safe to take in low doses — but always check with your doctor first. Green tea extract is not appropriate for children or teens.
Liver damage
The most serious risk you face when taking green tea extract is liver damage. Supplements high in catechins are more likely to cause liver damage when taken in extremely large doses. Very few green tea extracts have enough catechins to cause harm, but when green tea extract is used in bulk in weight loss supplements, you’re more likely to find these dangerous side effects.
There’s no clear scientific consensus on how or why this liver damage happens, but EGCG concentrates in the liver four times faster than it does in your blood. Some studies have shown that green tea extract also increases your alanine aminotransferase (ALT) levels, but it’s unknown if that’s a cause or an effect of liver damage.
These liver problems are more likely to occur when you take more than 800mg of EGCG per day. If you have a history of liver disease or a family history of acute liver failure, talk to your doctor before starting a green tea extract.
How Green Tea Extract Can Help You Control Your Appetite & Reach Your Happy Weight
Abby K. Cannon, JD, RD is an attorney turned dietitian who lives a very low waste lifestyle. She graduated from the University of Pennsylvania with a degree in psychology and received her law degree from Brooklyn Law School cum laude. She graduated from Queens College and became a registered dietitian in 2016.
Who doesn’t occasionally dream of a magic pill that will help you reach all your wildest health goals? While science has yet to make that wish a reality, some people are saying nature may have already done the work for us. Enter green tea extract. Supplement manufacturers are infusing this concentrated form of green tea into products that promise to help us control our appetites and reach our happy weights—naturally and without any side effects.
Sounds pretty great, but is it legit? Here’s what we know so far about what green tea extract does for weight loss, as well as the other health benefits of the antioxidant-rich substance.
Does green tea really help promote weight loss?
This super-concentrated version of green tea comes in powders, pills, and liquids that you can take during or after a meal to help boost your metabolism. And there’s good science to back it up: One study found that when 12 healthy men ingested green tea extract capsules and exercised for 30 minutes, their fat oxidation rates were 17 percent higher than when they consumed a placebo.
Those findings echo prior research on green tea extract for weight loss, which found that participants who consumed a beverage with the compounds found in green tea had higher rates of fat burning and a faster metabolism, both while exercising and resting. And in 2016, a study published in the journal Clinical Nutrition found that overweight women dropped about 2.5 pounds on average, saw decreases in their body mass index, and reduced their waist size when they took a high dose of green tea extract for 12 weeks.
Clearly there’s evidence backing up those green tea extract weight loss claims you might have seen online or at the grocery store. But how exactly does it work?
The secret lies in green tea extract’s high concentration of antioxidants called catechins, which have been correlated with a reduction in body fat. Green tea extract’s high caffeine content also likely plays a role in its weight loss benefits. One study found that people who consumed high amounts of caffeine and green tea lost more weight and fat mass than those who consumed less of it. Other research, published in Food Science and Biotechnology, found that caffeine can actually signal the body to break down fat. So it’s likely that the caffeine and antioxidants work in tandem as a catalyst for weight loss.
“When the green tea extract goes into the body, the antioxidants and caffeine enter the cells and help the body burn calories and fat,” said Liana Werner-Gray, a health and nutrition coach who specializes in weight loss at Complete Wellness NYC. “Green tea extract is a good, natural way to lose weight. We have so many studies to back it up.”
If you’ve already got some matcha in your pantry, you might be wondering: Can I lose weight by drinking a cup of green tea instead of taking the extract? Not quite. Swapping out heavier drinks, like soda and lattes, for green tea can certainly help you cut calories, but beyond that, drinking tea instead of taking green tea extract probably won’t give you the weight loss results you’re looking for. (However, that doesn’t mean it’s not a healthy practice!)
Is green tea extract harmful?
Green tea extract is high in potent antioxidants like EGCG. However, powerful antioxidants in supplement form are not always good for your health.
As the authors of a 2019 paper stated, “phytochemicals from supplements (as powder, tablet, and capsule) and natural whole foods have different effects the body, and continued consumption of supplements may also lead to negative effects.”
One reason is that whole foods not only contain beneficial antioxidants, but also offer nutrients and phytochemicals that can account for advantages that exceed the benefits of supplements.
According to a 2018 toxicology study of green tea and its extract, the observed safe level of daily EGCG consumption from drinking tea is 704 milligrams per day, but only 338 milligrams a day in the form of green tea extract or EGCG supplements.
In other words, brewing high-quality tea appears to be a safer way to obtain large amounts of healthful tea antioxidants compared to supplements.
Beyond the downsides of consuming high doses of antioxidants in supplement form, EGCG supplements may have other associated risks, too.
Similar to many dietary supplements, EGCG could interact with some prescription drugs. Speak to a physician before taking green tea extract if you currently take drugs for heart disease, sildenafil (Viagra), blood thinners, statins, or cancer drugs.
A few studies have shown signs of liver damage from green tea extract, such as elevated liver enzymes. These effects are rare, and probably nothing to worry about, but you should ask your doctor or health care professional before taking green tea extract if you have liver disease or liver function issues.
Is it safe to drink green tea every day?
It’s fair to say that superior evidence exists for the health benefits and safety of drinking green tea compared to taking green tea extract.
In fact, drinking a cup of green tea or more each day is not only safe, but it’s also the best way to obtain the most health benefits from green tea.
Epidemiological studies (population data) from Asian countries where daily green tea intake is the norm suggest virtually no adverse events aside from the possibility of excessive caffeine intake, and a modestly reduced risk of various health problems.
And as we discussed in the previous section, toxicology evidence suggests tea is a safer way to obtain EGCG and other green tea antioxidants than green tea extract and allows you to get over double the daily dose of green tea catechins without harm.
The quality of the tea you select and the method you use to brew it also affect the safety, catechin levels, and health benefits.
Low-quality teas have a higher risk of contamination with heavy metals, pesticides, fungi, and mycotoxins.
Finally, one study found that mountain-grown teas from China, harvested in the spring and brewed for 5-10 minutes at 176 degrees Fahrenheit (80 degrees Celsius), had the highest overall antioxidant content.
Should you prefer to avoid the possible bitterness of long steeps, steeping and re-steeping for shorter durations is another way to extract maximum levels of catechins from loose leaf tea. (18)
If you intend to drink tea daily for enjoyment or health benefits, be sure to choose high-quality teas from reputable retailers and prepare them correctly.
Final Thoughts
Green tea extract and related supplements like EGCG may be convenient, but the convenience comes with potential tradeoffs.
If you decide to purchase an extract, seek a reputable maker and ensure they use hot water extraction (and nothing else) to avoid contaminants like solvents left over from processing.
Even so, drinking real tea every day is a safer way to get higher doses of catechin antioxidants, and consumption of green tea is supported by far more health evidence than green tea extract supplementation.